From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A56A5C433E4 for ; Tue, 28 Jul 2020 19:25:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8C94A20656 for ; Tue, 28 Jul 2020 19:25:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732808AbgG1TZK (ORCPT ); Tue, 28 Jul 2020 15:25:10 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:44354 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728896AbgG1TZJ (ORCPT ); Tue, 28 Jul 2020 15:25:09 -0400 Received: from pps.filterd (m0098410.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 06SJ2bqg045957; Tue, 28 Jul 2020 15:24:57 -0400 Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 32jh6qtf15-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 28 Jul 2020 15:24:57 -0400 Received: from m0098410.ppops.net (m0098410.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 06SJ31G8047563; Tue, 28 Jul 2020 15:24:57 -0400 Received: from ppma02fra.de.ibm.com (47.49.7a9f.ip4.static.sl-reverse.com [159.122.73.71]) by mx0a-001b2d01.pphosted.com with ESMTP id 32jh6qtf0b-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 28 Jul 2020 15:24:56 -0400 Received: from pps.filterd (ppma02fra.de.ibm.com [127.0.0.1]) by ppma02fra.de.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 06SJOqEL029015; Tue, 28 Jul 2020 19:24:54 GMT Received: from b06cxnps3075.portsmouth.uk.ibm.com (d06relay10.portsmouth.uk.ibm.com [9.149.109.195]) by ppma02fra.de.ibm.com with ESMTP id 32gcq0thsf-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 28 Jul 2020 19:24:54 +0000 Received: from d06av24.portsmouth.uk.ibm.com (mk.ibm.com [9.149.105.60]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 06SJOpvU29032810 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 28 Jul 2020 19:24:51 GMT Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 73BE342042; Tue, 28 Jul 2020 19:24:51 +0000 (GMT) Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 6AE8B42047; Tue, 28 Jul 2020 19:24:48 +0000 (GMT) Received: from [9.85.75.143] (unknown [9.85.75.143]) by d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 28 Jul 2020 19:24:48 +0000 (GMT) Subject: Re: [RESEND PATCH v5 07/11] ppc64/kexec_file: enable early kernel's OPAL calls To: Michael Ellerman , Andrew Morton Cc: Pingfan Liu , Kexec-ml , Mimi Zohar , Nayna Jain , Petr Tesarik , Mahesh J Salgaonkar , Sourabh Jain , lkml , linuxppc-dev , Eric Biederman , Thiago Jung Bauermann , Dave Young , Vivek Goyal References: <159579157320.5790.6748078824637688685.stgit@hbathini> <159579233676.5790.10701756666641782647.stgit@hbathini> <87365b7nx4.fsf@mpe.ellerman.id.au> From: Hari Bathini Message-ID: <23baef6a-6ddc-572a-82c5-21a7fa441485@linux.ibm.com> Date: Wed, 29 Jul 2020 00:54:47 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <87365b7nx4.fsf@mpe.ellerman.id.au> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-07-28_15:2020-07-28,2020-07-28 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 clxscore=1015 priorityscore=1501 impostorscore=0 suspectscore=0 spamscore=0 phishscore=0 lowpriorityscore=0 mlxlogscore=997 bulkscore=0 mlxscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2007280131 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 28/07/20 7:16 pm, Michael Ellerman wrote: > Hari Bathini writes: >> Kernel built with CONFIG_PPC_EARLY_DEBUG_OPAL enabled expects r8 & r9 >> to be filled with OPAL base & entry addresses respectively. Setting >> these registers allows the kernel to perform OPAL calls before the >> device tree is parsed. > > I'm not convinced we want to do this. > > If we do it becomes part of the kexec ABI and we have to honour it into > the future. > > And in practice there are no non-development kernels built with OPAL early > debugging enabled, so it's not clear it actually helps anyone other than > developers. > Hmmm.. kexec-tools does it since commit d58ad564852c ("kexec/ppc64 Enable early kernel's OPAL calls") for kexec_load syscall. So, we would be breaking kexec ABI either way, I guess. Let me put this patch at the end of the series in the respin to let you decide whether to have it or not.. Thanks Hari